The mite fauna of the house-dust, collected from 39 houses of Seoul, were examined and the results are as follows. 1) Mites were present in 29 samples (74.3%) and the number of mites collected was 993 in total. 2) The families of the mites distinguished were Pyroglyphidae, Acaridae, Cheyletidae, Phytoseiidae and Smariidae, and the identified species were Dermatophagoides farinae, Deromatophagoides pteroassinus, Tyrophagus purtrecentiae, Landoglyphus konoi and Cheyletus malacensis. 3) D. farinae (53.6%) showed higher frequency rate of occurance than any other mites; C. malacensis (12.8%), T. putrecentiae (7.7%), D. pteronyssinus (5.0%) and I. konoi (2.7%).